Paper plates, Popsicle sticks, and a balloon are all you need to play Balloon Ping-Pong. (Not sure how sturdy the paper plates would be, but may be able to do something similar for a carnival/game night social event theme.
Don't throw away those empty bleach bottles -- transform them into an outdoor catching game! Cut the end off a cleaned bleach bottle and remove the label. Wrap the bottle with colorful tape, and you're ready to play catch!